A few weeks ago, there was an interesting discussion on the red line.  Here's an excerpt from a post from Andrew Song...

I got into using PT later then most and when I finally got to see my graphs, all my profits were coming from red-line first few years of my poker career. After a life threatening downswing after UIGEA, I talked a bunch and compared graph/stats with players who I respected and came to a conclusion that what I was doing wasn't optimal. I then put a ton of work to have my profit come from showdown and break even in non sd. I finally got what I wanted by late 08 and stuck to blue line game for majority of 2009. That year ended up being my worst year in my career if I exclude my winnings from playing live. I'm sure 40tabling had to hurt my hourly as well. Sometimes in early 2010, I came across GoMuk's well and was stunned to see that there's someone completely murdering the game with a style I tried so hard to give up. I insta PM'd him for coaching but he wasn't available since he was booked for next few months. Still, with the new found knowledge that red-line indeed works, I played. I ended up booking 70k month on February playing only 2/4 and 3/6. I think I won something like 140 buyin that month with 60k red-line profit. It was a revelation. Poker suddenly became fun for me again. Next month, Gomuk told me he's open for coaching and I took it. To be very honest I didn't learn much. I do believe that Gomuk is the best FR coach in the planet. It just didn't work for me since I was either too good 8-) or our approach to the game was very similar to start with. I did learn valuable skill that changed my winrate once and for all. Table selecting. That alone made the coaching worth way more then the dollar I paid. I guess I was a idiot thinking table selection is for pussies. I don't know how I got side tracked and ended up writing this tl;dr story. I bluffed my stack away in the $2000 FTOPS while writing this. I'm sure talking about red-line had to do with it. but what I wanted to say was that red-liners >>> blue-liners. I can't comment on which would be better for winrate because neither is the answer. If you want to talk about winrate, bum hunting would be the key.

What I do know is that red-line players are ALOT more tougher to play against. I much prefer playing tim0thee, nanonoko or robsainter then battling it out with I win flips, GoMuk, playinwitdreams or any reg that fights to win every pot. This alone pretty much should be the reason why redline > blueline. I do have long-term goals in poker to be able to reg toughest line up in 6handed+ 5k games and I think red-line is what will take me there unless the game changes drastically. In that case, I got more work to do. 

I think Andrew's post is one of the better posts I've seen in the MSFR FT regs' thread (altho that may not be saying much).  The only thing I would disagree on is that I prefer playing vs people who are too aggro than well-balanced.  Maybe because it's easier to win a monster pot off of those guys.  But that may just be my style of play.

The games have definitely gotten tougher the past few months, and part of it is the increased aggression in the games.  In the past, people would have folded when they knew they were beat - now they raise (and barrel off) to try and get folds from better hands.  People barrel any high card flop and they certainly keep barreling any overcards or scare cards.  3bet bluffing in position with playable hands is becoming the norm...  just to name a few examples.

However, I can't really see the FR games getting that much more aggressive.  Poker is a game of balance.  Raising your cbet from 50% to 60% will most likely be profitable.  But raising your cbet from 80% to 90% will probably be lighting money on fire.  The same principles apply to 3 betting, barreling, postflop raising, betting when checked to, and any other form of aggression.  But one of the most interesting things about poker is how the game changes, and seeing which of the regs (including myself) adapts the best.